Ueyama Tomoko, Arimura Takeshi, Takumi Koji, Nakamura Fumihiko, Higashi Ryutaro, Ito Soichiro, Fukukura Yoshihiko, Umanodan Tomokazu, Nakajo Masanori, Koriyama Chihaya, Yoshiura Takashi
1 Department of Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University , Kagoshima , Japan.
2 Department of Epidemiology and Preventive Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University , Kagoshima , Japan.
Br J Radiol. 2018 Jun;91(1086):20170453. doi: 10.1259/bjr.20170453. Epub 2018 Apr 16.
To identify risk factors for symptomatic radiation pneumonitis (RP) after stereotactic radiation therapy (SRT) for lung tumours.
We retrospectively evaluated 68 lung tumours in 63 patients treated with SRT between 2011 and 2015. RP was graded according to the National Cancer Institute-Common Terminology Criteria for Adverse Events version 4.0. SRT was delivered at 7.0-12.0 Gy per each fraction, once daily, to a total of 48-64 Gy (median, 50 Gy). Univariate analysis was performed to assess patient- and treatment-related factors, including age, sex, smoking index (SI), pulmonary function, tumour location, serum Krebs von den Lungen-6 value (KL-6), dose-volume metrics (V5, V10, V20, V30, V40 and VS5), homogeneity index of the planning target volume (PTV), PTV dose, mean lung dose (MLD), contralateral MLD and V2, PTV volume, lung volume and the PTV/lung volume ratio (PTV/Lung). Performance of PTV/Lung in predicting symptomatic RP was also analysed using receiver operating characteristic (ROC) analysis.
The median follow-up period was 21 months. 10 of 63 patients (15.9%) developed symptomatic RP after SRT. On univariate analysis, V10, V20, PTV volume and PTV/Lung were significantly associated with occurrence of RP ≥Grade 2. ROC curves indicated that symptomatic RP could be predicted using PTV/Lung [area under curve (AUC): 0.88, confidence interval (CI: 0.78-0.95), cut-off value: 1.09, sensitivity: 90.0% and specificity: 72.4%].
PTV/Lung is a good predictor of symptomatic RP after SRT. Advances in knowledge: The cases with high PTV/Lung should be carefully monitored with caution for the occurrence of RP after SRT.
确定肺肿瘤立体定向放射治疗（SRT）后出现症状性放射性肺炎（RP）的危险因素。
我们回顾性评估了2011年至2015年间接受SRT治疗的63例患者中的68个肺肿瘤。RP根据美国国立癌症研究所不良事件通用术语标准第4.0版进行分级。SRT每次分割剂量为7.0 - 12.0 Gy，每日一次，总剂量为48 - 64 Gy（中位数，50 Gy）。进行单因素分析以评估患者和治疗相关因素，包括年龄、性别、吸烟指数（SI）、肺功能、肿瘤位置、血清肺表面活性物质相关蛋白A值（KL - 6）、剂量体积指标（V5、V10、V20、V30、V40和VS5）、计划靶体积（PTV）的均匀性指数、PTV剂量、平均肺剂量（MLD）、对侧MLD和V2、PTV体积、肺体积以及PTV/肺体积比（PTV/Lung）。还使用受试者操作特征（ROC）分析来分析PTV/Lung在预测症状性RP方面的表现。
中位随访期为21个月。63例患者中有10例（15.9%）在SRT后出现症状性RP。单因素分析显示，V10、V20、PTV体积和PTV/Lung与≥2级RP的发生显著相关。ROC曲线表明，可使用PTV/Lung预测症状性RP[曲线下面积（AUC）：0.88，置信区间（CI：0.78 - 0.95），临界值：1.09，敏感性：90.0%，特异性：72.4%]。
PTV/Lung是SRT后症状性RP的良好预测指标。知识进展：对于PTV/Lung高的病例，应谨慎密切监测SRT后RP的发生。
